Heparin resistance during cardiopulmonary bypass.

The hemostatic system is activated during cardiopulmonary bypass (CPB) procedures, and the use of heparin attenuates the coagulation. However, heparin resistance occurs in between 4 and 22% of patients undergoing cardiac surgery, and the preoperative use of heparin is usually responsible for this. Sometimes, critically ill patients are referred for intra-aortic balloon pump (IABP) insertion, and anticoagulation therapy with heparin is recommended to prevent thrombosis and embolization. The author experienced heparin resistance in patients who underwent percutaneous coronary intervention (PCI) and IABP insertion.